Vehicle restraint

ABSTRACT

Vehicle restraint including a support mounted adjacent a loading structure. A carriage is supported from the support and has a generally horizontal portion extending over the roadway, the horizontal portion being operatively engageable with the vehicle bar over a vertical range. A vertically elongate barrier is supported from the carriage and is disposed remotely from the upright loading structure, the barrier being mounted for generally vertical movement with respect to the carriage between an inoperative vehicle-released position wherein the barrier is disclosed below the horizontal portion, and an inoperative vehicle restraining position, wherein the barrier extends vertically a fixed distance above the horizontal portion to define a vehicle bar capture distance along the horizontal portion.

This is a continuation of application Ser. No. 08/173,411 filed on Dec.23, 1993, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to safety equipment for use inconjunction with a loading dock, and specifically to a vehicle restraintto prevent accidental or unauthorized moving of a parked vehicle awayfrom the dock while the vehicle is being loaded or unloaded.

2. Description of the Prior Art

Proper securing of a parked vehicle to a loading dock during loading orunloading is an essential safety precaution. When a securement system isnot in place, the vehicle may accidentally or inadvertently be movedaway from the dock. This in turn may result in serious injury to thedock personnel, as well as product damage or loss of the cargo beingmoved.

To prevent a parked vehicle from moving during such loading andunloading operations, a variety of vehicle restraints have previouslybeen employed. In general, such restraints are mounted to the face ofthe loading dock, or the driveway approaching it, and include a hook orother retaining member which has a generally horizontally extending legand a vertical projection and which restrains a vehicle bar suspendedfrom the rear end of the parked vehicle. Typically, the vehiclerestraint engages a horizontally disposed bar suspended from the rear ofthe vehicle as mandated by ICC regulations. Such a vehicle bar will bereferred to herein as an ICC bar. An example of a vehicle restraintengaging a vehicle bar in the form of an ICC bar can be seen in U.S.Pat. No. 4,443,150 to Hahn, et al. the disclosure of which isincorporated herein by reference. In that type of vehicle restraint, thehook is carried within a vertically movable carriage. The carriage isbiased upwardly and includes a sloping cam surface, which is engaged bythe ICC bar as the truck backs into position to push the carriagedownward from its elevated rest position. When the truck is fully backedin, the ICC bar is in engagement with a top surface of the carriage. Thehook including the leg and vertical projection is then moved as a unitvertically from its rest position inside the carriage to itsvehicle-engaging position wherein the ICC bar is captured behind thevertical projection of the hook.

Certain other restraints have used a pivotal hook movement wherein theretaining hook rotates from a stored position to a vehicle-engagingposition such as in U.S. Pat. No. 4,264,259 to Hipp. That restraint hasa movable carriage similar to that of the '150 patent, but the hook ispivotally mounted within the carriage. Pivotal movement of the hookplaces the vertical projection in a position where it can capture an ICCbar of a properly parked vehicle. The vehicle restraint of U.S. Pat. No.4,759,678 to Hageman also shows pivotal movement of a hook housed withina carriage.

The types of restraints just described have used both manual andpower-driven means for moving the hook. The '150 patent shows manualvertical movement of the entire hook, including the horizontal leg andthe vertical projection. The '259 and '678 restraints both show pivotalmovement of the hook by power-driven means which are external to thecarriage. A further U.S. Pat. No. 4,472,099 to Hahn, shows a pivotinghook and a power-driven means housed within the carriage.

When the powered drive is external to the carriage, it may be subject todamage from the truck itself, or other external forces. Housing thepowered drive in the carriage allows for protection from outsideelements, but makes it susceptible to damage from uncontrolled movementof the hook or carriage. Further, housing of the powered drive for ahorizontally-extending hook in the carriage limits the size of the drivesince the hook itself requires space within the carriage--both forhousing the hook and for allowing it unimpeded travel. As a result, thepowered drive has less output capacity, and less ability to withstandexcessive forces from uncontrolled movement of the hook or carriage, orfrom an attempt to move the vehicle while restrained. The problem of alow output capacity for the drive may be compounded by the fact that thehorizontal leg and vertical projection of the hook make the hookrelatively massive. Further still, a mounting of the powered drive inthe carriage may require complex power-transfer mechanisms such as barlinkages and the like for moving the hook as in the '099 patent. This isparticularly true in the case of a linearly moved horizontally-extendinghook, since a vertical force must be applied to a member having asignificant horizontal extent.

In the situation where the hook is moved manually, a significant forcemust be applied to move the hook including the relatively massivehorizontal leg and vertical projection to its elevatedvehicle-restraining position. Further, some means, such as a latch orother engaging mechanism, must be employed to maintain the entire hookincluding the horizontal leg and vertical projection in the elevatedposition. Thus, while these devices are effective in restraining aparked vehicle, they have certain shortcomings.

SUMMARY OF THE INVENTION

It is thus a primary aim of the present invention to provide a vehiclerestraint which minimizes the previously mentioned shortcomings presentin prior devices of this type.

In accordance with that aim, it is an object of the present invention toprovide a vehicle restraint, including an independently movablecarriage, and employing a simplified vehicle restraining member that ishoused within the carriage.

It is a further object to provide a vehicle restraint in which thepowered drive for moving the vehicle restraining member is simple inconstruction and does not occupy an undue amount of space inside thecarriage.

It is a related object to provide a vehicle restraint in which a complexpower-transfer means from the powered drive to the vehicle restrainingmember is not employed.

It is also an object of the invention to provide a vehicle restraint inwhich the powered drive is less susceptible to damage from uncontrolledcarriage movement, or from a force exerted on the vehicle restrainingmember from efforts to move a restrained vehicle.

It is a feature of the present invention that the vehicle restrainingmember is a vertical barrier, without an extended horizontal projection,that reciprocates vertically between an inoperative position inside thecarriage and a vehicle-restraining position.

It is also a feature of the invention that the powered drive is housedwithin the vehicle restraining member when that member is in theinoperative position.

It is a further feature that the powered drive is releasably coupled tothe vertical barrier such that the vertical barrier can moveindependently of the drive.

It is a further feature of the invention that the vehicle restraintincludes signalling mechanisms for improving the safety of the vehiclerestraint and the loading dock environment and cooperative meansproviding an integrated system of sensing and controlling the carriage,restraining device and operational information devices.

In accordance with these and other objects and features of theinvention, there is provided a vehicle restraint for securing a vehicleparked on a roadway relative to an adjacent structure. The vehiclerestraint includes a support mounted on or to the face of the adjacentstructure directly or indirectly. A carriage is mounted to the supportfor substantially vertical movement with respect thereto. At least onespring or bias device is connected between the support and the carriagefor biasing the carriage to yieldably assume an elevated position. Thecarriage is movable downwardly from the elevated position upon anexternal force of a sufficient magnitude being exerted on the carriage.The vehicle restraint also includes a vertically elongate barriermounted within the carriage for substantially vertical movement withrespect to the carriage between an inoperative vehicle-release positionwherein the barrier is disposed within the carriage, and an operativevehicle-restraining position wherein the barrier extends verticallyabove a horizontal top surface of the carriage. To effect movement ofthe vertical barrier between the inoperative and the operative position,a driver is also provided. The driver may either be powered or some formof non-powered means such as a spring or other bias mechanism.

According to a preferred embodiment of the invention, the carriageincludes two side plates having a front section that includes anupwardly and rearwardly extending cam surface, which is engaged by theICC bar of an entering vehicle to exert a downward force on thecarriage. The top surface of the vertically moveable barrier has asimilar sloping surface that is disposed between and just below the sidesection camming surfaces when the vertical barrier is in the inoperativeposition. One embodiment of the vehicle restraint also includes a sensormember that is biased to extend above the horizontal top surface of thetwo side plates. A properly positioned ICC bar presses down on thesensor to make its top surface flush with the top surface of the sideplates. As a result, a contact switch attached to the sensor assumes anoperative position. That position can be utilized to actuate audio orvisual devices providing operational information or warnings. Also, inthe operative position a switch-engaging member on the vertical barrierdepresses the switch when the barrier assumes its fully extendedposition. The closing of the switch with the ICC bar depressing thesensor and the vertical barrier fully extended serves as an indicationthat the vehicle is being restrained by the vehicle restraint.Ultimately, this closing of the contact switch may serve as a controlfor limiting the upward travel of the vertically travelling barrier.

According to an alternative embodiment, a manual version of the vehiclerestraint is provided. A spring or other biasing mechanism is housedwithin the vertical barrier and serves to move the barrier toward theoperative position. A latching mechanism secures the vertical barrier inthe inoperative position. Release of the latch allows the barrier torise to its operative position. To return the vertical barrier to theinoperative position, a manually-actuated latch is provided. Themanually operated vehicle restraint may or may not include the sensor,but in any event may also include advantageous signalling and safetyfeatures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vehicle restraint according to thepresent invention;

FIG. 2 is a side sectional view of the vehicle restraint according tothe invention;

FIG. 3 is an exploded side view of the vehicle restraint according tothe invention;

FIG. 4 is an exploded front view of the vehicle restraint according tothe invention;

FIG. 5 is a sectional view of the vehicle restraint according to theinvention in the inoperative position;

FIG. 6 is a sectional view of the vehicle restraint according to theinvention in the operative position;

FIG. 7 is a side section view of the vehicle restraint according to theinvention showing a first fault condition;

FIG. 8 is a side sectional view of the vehicle restraint according tothe invention showing a second fault condition;

FIG. 9 is a top elevational view of the vehicle restraint according tothe invention;

FIG. 10 is a side sectional view of a manual version of the vehiclerestraint according to the invention in the inoperative position; and

FIG. 11 is a side sectional view of a manual version of the vehiclerestraint according to the invention in the operative position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention relates to an improved vehicle restraint for securing avehicle parked on a roadway adjacent a loading structure, and oneembodiment of the present invention is shown in FIG. 1. The vehiclerestraint 10 is mounted on or adjacent to the front face F of a loadingdock D. A roadway R extends away from the face F of the dock. Thevehicle restraint 10 is adapted to capture a vehicle bar depending fromthe rear of the vehicle. For the purpose of illustration herein,reference will be made to a vehicle bar in the form of an ICC bar. Thevehicle restraint 10, in FIG. 1, captures the ICC bar (shown in phantom)of the parked vehicle which is parked adjacent to the dock D on theroadway R. With the ICC bar retained in this fashion, the vehicle isprevented from pulling from the face of the dock in the directionindicated by the arrow 12. Such restraint of the vehicle not onlyprevents the vehicle from accidently and inadvertently rolling away fromthe dock D during unloading and loading, but also prevents the driverfrom accidentally driving the vehicle away during the same operations.As can be appreciated, movement of the vehicle away from the dock Dduring unloading or loading operations could be hazardous to any of thedock personnel performing these functions.

As can be seen from FIG. 1, the ICC bar of the parked vehicle iscaptured behind a barrier 20 extending upwardly from a roughlytrapezoidal-shaped housing or carriage 30. The barrier 20, to bediscussed in greater detail below, reciprocates vertically relative tothe carriage between an operative, vehicle-restraining position of FIG.1, and an inoperative position where barrier 20 is disposed fully withinhousing 30. Housing 30 maintains the desired spacing of the verticalbarrier 20 away from face F, and also positions the barrier foreffective movement between its operative and inoperative positions.

Housing 30 is formed of two side plates 31 and 32 defining spacedplanes, and which have the same shape (i.e. are congruent) and aredisposed parallel to each other to define a housing interior volumedesignated generally by reference numeral 35. A variety of othercomponents making up the vehicle restraint, also to be described ingreater detail below, are disposed within this interior volume.

To secure the housing 30, and its associated components relative to theface F of the dock, a support 50, having a guide section includingchannels 58 and 59, is mounted adjacent the loading structure either onor adjacent to the face F of the dock. The support 50 of this embodimentincludes a back plate 52 which may illustratively be mounted to the faceF of the dock by means of bolts 54. Alternatively, the support 50 couldinclude a back plate attached to a second plate which is fixed to theroadway R instead of to dock face F. In the present embodiment, theguide section also includes a pair of guide brackets 56 and 57 which aremounted to the back plate 52 to form the two vertical channels 58 and59. The carriage 30 which is mounted for vertical movement on the guidesection, includes suitable roller assemblies 60. These horizontallyextending roller assemblies 60 are adapted to fit within verticalchannels 58 and 59. In this manner, the carriage 30 is mounted forvertical movement on the guide section 50.

The vehicle restraint 10 is shown in its vehicle-restraining oroperative mode in FIG. 1. As mentioned, the vehicle restraint 10 alsohas an inoperative mode wherein the vertical barrier 20 moves generallyvertically to a position wherein it is fully disposed within thecarriage 30. Movement of the barrier 20 from this inoperative positionto the operative position shown in FIG. 1 will only result in capture ofthe ICC bar if that bar is disposed along the horizontal top surface 37of the carriage 30 within the capture distance 21, between dock face Fand an extended vertical barrier 20. That is, an ICC bar will only becaptured by the barrier 20 extending vertically out of carriage 30 ifthere is proper orientation of the ICC bar with respect to the carriage30 and the barrier 20 such that the ICC bar is disposed between thebarrier 20 and the face F of the dock.

The means by which this proper orientation of the ICC bar and thebarrier 20 is achieved will now be described in greater detail. Thecarriage 30 is biased to yieldably assume an elevated position. To biasthe carriage to this elevated position, a bias device illustratively inthe form of a spring 65 is operatively connected to the guide section 50and to the carriage 30. (See FIG. 2). As can be seen from FIG. 2, thesprings 65 are mounted on either side of brackets 56 and 57, shown inFIG. 1. A spring mounting bracket 61 is stationary and fixed to the backplate 50, and includes a receiving hole 62 for receiving an upperprojection from spring 65. A lower projection from spring 65 is mountedto a spring anchor 63, which is in turn fixed to carriage 30. Springanchor 63 extends outwardly from sidewalls 31, 32, and is fixed tocarriage 30 by bolts 64. Although only one spring 65 has been mentioned,several springs could comprise the bias device. Moreover, a variety ofconfigurations of spring anchor 63 could be used, so long as they arefixed to the carriage 30 and are adapted for receiving an end of aspring, springs, or other biasing device. Moreover, although extensionsprings are shown, compression springs, gas springs, or other biasdevices, could be mounted below the carriage and used for upward biasingof the carriage.

The carriage 30 is biased to an elevated position, usually severalinches higher than the range of ICC bars. The backing in of a vehicle,and engagement of its ICC bar with the restraint will cause the carriage30 to move downward to a position such that the proper orientation ofthe ICC bar and the vertically-extending barrier 20 can be achieved.Toward that end, carriage 30 includes an upwardly and rearwardly slopingcam surface 38. When the ICC bar of a parking vehicle engages thecamming surface 38, the carriage 30 will be forced downwardly as themagnitude of the downward force exerted by the ICC bar on the cammingsurface overcomes the effect of the spring 65. The stiffness of thespring 65 is selected such that contact of an ICC bar of a parkingvehicle will overcome the bias of the spring 65 without causing damageto the building, restraining device, or ICC bar. As the vehiclecontinues to back into position, the carriage continues to ride downwith the cam surface 38 remaining in contact with the ICC bar, thusfurther lowering the carriage 30. As the vehicle approaches the dockface, the ICC bar engages the horizontal surface 37 to properly positionthe horizontal surface relative to the ICC bar, and to limit upwardmovement of carriage 30. With the ICC bar adjacent the horizontalsurface, the orientation of the ICC bar is now such that the ICC bar iswithin a capture distance 21 which is defined by the horizontalseparation of barrier 20 at the distal end of the carriage from face F.The vertical barrier 20 can now be moved to its operative position shownin FIG. 1 and capture the ICC bar between the barrier 20 and face F torestrain the vehicle.

According to this arrangement, the relative vertical position of thehorizontal surface 37 and barrier 20 is controlled by the height of theICC bar above the roadway. As long as the ICC bar is within the verticalrange of movement of the carriage 30, the carriage 30 can move so thatthis configuration is achieved. This in turn leads to one of theadvantageous features of the present invention.

To allow the vehicle restraint 10 to be adaptable to a wide range ofheights of ICC bars and especially low ICC bars, an elongated toe-likemember 80 is pivotally mounted to the front section of the carriage 30as more fully described in U.S. Pat. No. 4,560,315 and U.S. Reissue Pat.No. Re. 32,968. Since the exact height of an ICC bar is not carefullyregulated, they may be at a variety of heights above the roadway. In avehicle restraint without toe-like member 80, it would be possible foran ICC bar of a vehicle to be low enough to pass beneath the cam surface38 of the carriage.

The bias device in the form of spring 65 further serves to maintain thecapture of the ICC bar during the entire loading and unloadingoperation. As material is loaded onto a parked vehicle, the added weightof the cargo may cause the vehicle, and thus the ICC bar, to assume alower position. Conversely, as the truck is unloaded the suspensionsystem on the truck may cause it to assume a higher position due to alesser cargo weight. The magnitude of this change depends upon theparticular truck suspension. Such movement of a parked vehicle duringloading and unloading is generally referred to as "float" of thevehicle. The action of the bias device 65 in the vehicle restraint 10allows the restraint to accommodate such vehicle float. Since thecarriage 30 is biased upwardly by the bias member 65, any upward floatof the truck due to unloading will result in the carriage also movingupward under bias from the bias member 65 so that the ICC bar maintainscontact with the horizontal surface 37 of the carriage. Thus, thevertical relationship of the barrier 20 to the ICC bar will remainunchanged. Similarly, as the vehicle and its attached ICC bar movedownwardly due to loading, the upward force of the bias member 65 isovercome and the carriage 30 is pushed downwardly. By means of the biasdevice, then, the I.C.C. bar always maintains contact with thehorizontal surface 37 and thus remains captured along the horizontalsurface 37 of the carriage and behind the barrier 20 when it is in itsextended position.

Thus far, various structures of vehicle restraint 10 have beendescribed, such structures place and maintain carriage 30 in a positionsuch that movement of the barrier 20 to the operative position willdefine a restraint envelope for the parked vehicle. Furthermore, thestructure of the vehicle restraint which allows the restraint to followthe upward and downward float of a truck during loading and unloadinghas been described. The operation of the barrier 20 and various othercomponents of vehicle restraint 10 which are housed within the internalvolume 35 of the carriage 30 will now be described in greater detail,along with their various functions.

An exploded view of the components of vehicle restraint 10, according tothis embodiment of the invention, are shown in FIGS. 3 and 4. Thevertically elongate barrier 20 is mounted within the carriage 30 forgenerally vertical movement with respect to the carriage between aninoperative, vehicle-release position, shown most clearly in FIG. 5, andan operative vehicle-restraining position shown most clearly in FIG. 6.In the inoperative vehicle-release position the barrier is disposedfully within the carriage 30. In the operative, vehicle-restrainingposition, the barrier extends vertically above the horizontal topsurface 37 of the carriage.

The vertical barrier 20 includes two side walls and front and rear wallswhich define an open interior volume. The vertical barrier 20 alsoincludes a sloping top surface 23 which is parallel to the sloping camsurfaces 38 of the side plates 31 and 32. With the vertical barrier inthe inoperative, vehicle-release position the sloping surface 23 of thebarrier is disposed between and slightly below the camming surfaces ofthe side plates. The positioning of this sloping surface 23 slightlybelow the surface of the camming surfaces 38 of the carriage preventsundue wear of this surface of the barrier by repeated sliding contactwith an approaching ICC bar. At the same time, the fact that the slopingsurface 23 is parallel to the camming surface 38 allows the verticalbarrier to be disposed as close to the exterior of the carriage aspossible.

To provide for movement of the vertical barrier between the inoperativean operative positions, a driver 90 is included which is housed withinthe carriage 30 and also within the open interior volume of verticalbarrier 20. According to the present embodiment, the driver 90 is ascrew drive which includes an external cylinder 92 and a screw-drivenpiston 94 which moves in and out of cylinder 92. Piston 94 is shown inits withdrawn position in FIG. 3, and in its extended position in FIG.6. Driver 90 is mounted within carriage 30 by means of a clevis pin 96,shown most clearly in FIG. 4. As reference letter A in FIG. 4 indicates,clevis pin 96 is fed through a projection 97 on the bottom of driver 90.On either side of the projection 97 and between side walls 31 and 32,there are also included cylindrical sleeves 98 and 99 which fit overthis pin 96. These cylindrical collars, along with the clevis pin serveto limit the downward motion of the vertical barrier 20.

As can be seen in FIG. 3, the vertical barrier 20 may include a notch 24in each of its side walls. As the vertical barrier 20 is lowered fromits operative position to its inoperative position, this notch engagesthe cylindrical collars 98 and 99 disposed on the clevis pin therebypreventing any further downward movement of the vertical barrier 20.Such an arrangement protects the driver 90 from being unduly damaged bya lowering vertical barrier 20. Moreover, this arrangement allows thedriver 90 to be fully housed within the interior volume of the verticalbarrier 20 when the vertical barrier is in the inoperative position.This aspect can be seen most clearly in FIG. 5. This is advantageousbecause not only because the driver is protected by being housed withinthe barrier, but also because it allows the driver to occupy a minimumamount of space within the carriage 30. As an alternative, the notches24 could be omitted so that the bottom surface of barrier 20 would reston the collars 98 and 99.

To further protect the driver 90 and to improve the performance of thevehicle restraint 10, the driver is releasably coupled to the verticalbarrier to allow for independent movement of the barrier relative to thedriver. In the present embodiment, this releasable coupling is achievedby means of a driver block 100 being attached to the piston 94 of thedriver 90. In turn, this driver block makes a contacting engagement withthe interior surface of the vertical barrier 20, as can be seen in FIG.4, the driver block 100 is attached to the end of piston 94 by means ofa pin 101. The releasable contact between the driver 90 and the verticalbarrier 20 prevents the driver 90 from being damaged by a sudden upwardmovement of the vertical barrier 20. Such movement of the verticalbarrier could occur, for example, by virtue of someone using the vehiclerestraint to step up or down from the loading dock. Since the biasmember 65 would be stretched by virtue of that person's weight, theperson jumping off the carriage would cause a sudden upward movement ofthe carriage by means of the bias device. When the carriage reaches itsupper limit of travel, however, its upward movement, would abruptlystop, but that of the vertical barrier 20 would not. In such asituation, a permanent connection between vertical barrier 20 and thedriver 90 could result in an undue pulling force being exerted on thepiston 94 thus damaging the screwdrive 90. By making the connectionbetween the driver 90 and the vertical barrier 20 releasable, Such unduedamage to the driver is avoided.

The vertical barrier 20 which moves under the influence of driver 90, isguided in its substantially vertical movement by means of guide blocksmounted on the side sections 31 and 32. The guide blocks 110 and 111 areshown mounted to their respective side sections 31 and 32 in FIGS. 3 and4. In FIG. 5, guide section 110 is shown in its orientation with respectto the vertical barrier 20. As can also be seen from FIG. 5, a spacerblock 115 is also disposed between the side sections 31 and 32. Each ofthe guide blocks 110 and 111, along with the spacer block 115 includesurfaces for contacting and guiding the barrier 20 during itssubstantially vertical movement. Furthermore, as can be seen in FIG. 6,these same surfaces contact the barrier 20 when the barrier is in theextended, vehicle-retaining position. This contact between the spacerblock 115 and guide blocks 110, 111 and the vertical barrier 20 preventtransverse movement of the barrier 20 when it is in the operativeposition. Such transverse movement is undesirable since it could allowthe barrier 20 to slope forward. Were this to occur it would be possiblefor a vehicle to drive away from the dock and defeat the vehiclerestraint. Thus, the contact between the spacer block 115 and guideblocks 110, 111 to maintain the substantially vertical position of thebarrier 20 forms an important aspect of the present invention. Thespacer block 115 and guide blocks 110, 111 thus resist any horizontalforces applied to the barrier 20 by an ICC bar. Such horizontal forceson the barrier 20 actually cause a torque to be placed on the barrier.In reference to FIG. 6, the moment arm of this torque is the distancebetween the contact B of the ICC bar with the barrier 20, and thecontact A of the barrier 20 with the spacer block 115. Because carriage30 is vertically adjustable to accommodate different ICC bar heights andvehicle float, the moment arm will always have this relatively smallsize. This is advantageous as compared to vertical barrier restraintswhich do not account for float, since a less robust structure can beused in this restraint. According to a further feature of the invention,this moment arm is substantially constant although slight variationscould be introduced by different shapes of ICC bars. This is due to thefact that a captured ICC bar will always be on the horizontal surface37. Thus, any horizontal force exerted on the barrier 20 by the ICC bar20 will always be at substantially the same vertical position B on thebarrier 20 regardless of the height of the ICC bar relative to theroadway and the distance between B and the pivot point A is always thesame. The constancy of the moment arm is advantageous since varyingmoment arms do not have to be accounted for in designing this vehiclerestraint to withstand a given maximum horizontal force.

The spacer block 115 serves the further purpose of capturing thevertical barrier 20 within the carriage 30. As can be seen most clearlyfrom FIGS. 5 and 6, vertical barrier 20 includes a stop bar orprojection 24 from the front surface thereof. This projection 24 isadapted to engage the bottom surface of spacer block 115 if the vehiclebarrier 20 moves vertically beyond a certain position. This contactbetween stop bar or projection 24 and spacer block 115 thus prevents thevertical barrier 20 from leaving the carriage. This prevents thevertical barrier 70 both from being removed without proper tools fromout of the carriage, and from ejecting from the carriage in thesituation described earlier as an abrupt stop of the carriage assembly30.

In addition to the components described above which serve to correctlyposition the carriage with respect to the ICC bar, and to capture aproperly positioned ICC bar, the vehicle restraint 10 according to thepresent invention also includes several features which enhance itssafety as well as ease of operation. The vehicle restraint 10 includes asensor member 120, the operation of which allows a signal to begenerated which indicates that a parked vehicle is properly restrainedand that loading and unloading can begin. The sensor member 120 whichcan be seen most clearly in FIG. 3, is mounted within the carriage 30for reciprocating vertical movement with respect to the carriage. Underthe influence of the ICC bar of a parked vehicle, the sensor member 120moves between an extended position shown in FIG. 5 and a depressedposition shown in FIG. 6. In the extended position, an upper surface 122of the sensor member extends above the horizontal top surface 37 of thecarriage 30. In the depressed position, shown in FIG. 6, the upperhorizontal surface 122 of the sensor member 120 is disposed between thehorizontal top surfaces 37 of the carriage 30. A contact switch,attached to the sensor 120 in a manner to be described below, movesalong with the sensor member in its reciprocating vertical motionbetween the extended and depressed position. Movement of the sensormember 120 to the depressed position under the influence of a properlyplaced ICC bar moves the contact switch 130 to an operative positionwhereby movement of the vertical barrier 20 to its operative positionwill cause the contact switch 130 to close. Since the contact switch 130is only brought to this operative position if an ICC bar is in theproper position for being restrained by an extended barrier 20, thisclosing of the contact switch serves as an indication that the vehicleis properly restrained. The contact switch 130 may be connected toassociated electronics (not shown) which can generate a visual signal toboth dock personnel and to the vehicle driver that the vehicle isproperly restrained, and can thus be loaded or unloaded.

Since the contact switch 130 is only closed when both (1) the sensor isdepressed by a properly positioned ICC bar, and (2) the vertical barrier20 is extended to its operative, vehicle engaging position, non-closureof the contact switch 130 can serve as an indication that a vehicle isnot properly restrained. Such "fault" conditions are illustrated inFIGS. 7 and 8. In FIG. 7, an ICC bar is not present. As a result, thesensor 120 has not been depressed, and the contact switch 130 is thusnot properly positioned in the operative position. Thus, even thoughvertical barrier 20 is in its extended, vehicle-restraining position,the contact switch 130 is not closed.

In the fault position shown in FIG. 8, the ICC bar is present, but dueto its improper positioning, the vertical barrier 20 has been preventedfrom rising to its fully extended position. Since the sensor 120 isdepressed, the contact switch 130 is in the operative position. However,because the barrier 20 is not fully extended, the contact switch has notbeen closed. In either of these cases, the non-closure of the contactswitch prevents the representative signal from being sent to the controlelectronics. As a result, no visual signal that the vehicle is lockedwould be displayed, and both the dock personnel and the vehicle driverwould be alerted to a fault condition.

The sensor member 120 is biased into the extended position by means of asensor biasing device, illustrated as compression springs 140 in FIG. 5.The springs 140 are disposed between the sensor member 120 and a postreceiving block 150 which is mounted between side panels 31 and 32 ofcarriage 30. The post receiving block includes three spaced holes whichreceive posts 160 which extend downwardly from the sensor member 120, asis shown most clearly in FIG. 3. The springs 140 maybe adapted tosurround the post 160. Furthermore, sensor member 120 may includerecesses 162 for receiving the upper end of the springs 140, as shown inFIG. 3. With the springs 140 in place and the post 160 engaged in theholes in the post-receiving block, sensor member 120 is biased into itsextended position. This biasing ensures that the sensor member will onlybe in its depressed condition and the contact switch 120 will only be inits operative position when a properly positioned ICC bar is in placeand depresses the sensor. The compressive strength of the compressionsprings 140 is substantially less than the force necessary to depressthe carriage 30.

The contact switch 130 is connected to one of the downwardly extendingposts from the sensor member 120 to ensure that the contact switch 130vertically reciprocates along with the sensor member 120. As can be seenmost clearly seen in FIGS. 3 and 4, the contact switch 130 is mounted toa switch receiving bracket 170 by means of bolts 172. This switchreceiving bracket 170 is, in turn, mounted to one of thedownwardly-extending posts 160 which is threaded for that purpose.According to this embodiment of the invention the central downwardlyextending post is used to attach to the contact switch bracket 170.

The sensor member 120 also includes front and rear sloping portionsdesignated respectively as 123 and 124 (FIG. 5). With the sensor member20 in the extending position, front sloping surface 123 serves as aneffective extension of the front sloping surface of the carriage 30.Thus, as an ICC bar moves up the camming surface 38 it will also contactsloping surface 123 and cam the sensor member 120 downward into thedepressed position.

To provide for contact between the vertical barrier 20 and the contactswitch 130 when the sensor member is in the depressed position, and thevertical barrier 20 is in the operative vehicle-restraining position,the vertical barrier 20 includes a switch engaging portion in the formof a strip 180 on a rear surface of the barrier. This switch engagingstrip 180 is a formed piece of spring steel, and can be most clearlyseen in FIG. 3. The switch engaging strip 180 includes an elongateddownwardly extending contact portion 182. The shape of the formed springsteel member ensures that the downwardly extending contact portion 182is biased away from the rear surface of the barrier. The fact that thecontact portion 182 is elongated downwardly means that contact with thecontact switch 130 can occur over some defined range of vertical motionand over a defined range of horizontal motion. As a result, the biasingof the member 180 away from rear surface of the barrier allows forsubstantial vertical and horizontal movement between the barrier and thesensor, while still maintaining the contact between the contact portion182 and the contact switch 130. Such relative vertical and horizontalmovement may occur due to external forces including vibration and motionof the restrained vehicle or carriage 30. The structure of the switchengaging strip 180 ensures that such relative vertical and horizontalmovement will not cause the switch engaging strip to lose contact withthe contact switch and thus generate a fault condition when the vehicleis actually properly restrained.

The vehicle restraint 10 also includes a lower contact switch 190, whichcan generate an indication that it is safe for the vehicle to pull awayfrom the dock. As can be seen in FIGS. 3 and 4, this lower contactswitch 190 is fixed to side section 31. The contact switch 190 ispositioned such that it is engaged by the rear surface of the verticalbarrier 20 when the vertical barrier is in the inoperativevehicle-release mode. Closure of contact switch 190 thus serves as anindication that the vehicle is no longer being restrained and may besafely driven away from the dock. An electrical signal generated byclosure of the switch may be provided to the control electronics (notshown) so that they can provide a visual signal to the vehicle driverthat it is safe to leave the dock.

The sensor member 120, along with the barrier 20 and spacer block 115,also protect the carriage interior volume from contamination from above.Referring to FIG. 9, which is a top view of the restraint 10, it can beseen that these three components effectively form a cover for the top ofthe restraint 10. This is true when the sensor and barrier are in eithertheir extended or depressed positions.

In the embodiment of the vehicle restraint just described, a powereddriver 90 was used to move the vertical barrier 20 between itsinoperative and operative positions. According to an alternativeembodiment of this invention, a non-powered means may be employed forthe same purpose. An example of such vehicle restraint can be seen inFIGS. 10 and 11. Although this embodiment of the invention may includeall of the signalling features described above, they have been omittedfrom FIGS. 10 and 11 for ease of reference. Rather, these figures onlyshow the actuation mechanism for movement of the barrier, and the meansfor retaining the barrier in the inoperative position.

To move the barrier between the inoperative and operative positions, aresilient device is used, according to the present invention theresilient device is an extension spring 200. The spring 200 is disposedon a cylindrical member 205 which serves to guide and retain the spring200. Like the driver 90 of the previous embodiment, this cylindricalmember 205 is secured between the side plates of the carriage 30 bymeans of a clevis pin 210. As is also true in the previous embodiment,this clevis pin includes cylindrical sleeves which are adapted to fitwithin the engaging notch 24 of the vertical barrier 20 to prevent itsfurther downward movement. The vertical barrier includes a horizontalplate 220 including a central opening 222 for receiving the cylindricalmember 205. Spring 200 releasably engages the bottom surface of thishorizontal plate 220 for exerting an upward force on the barrier member20 to move it to is operative vehicle-engaging position.

To maintain the vertical barrier 20 in its inoperative position and tomaintain the spring 200 in its compressed condition, a latch mechanism230 is employed. The latch mechanism is coupled to the vertical barrier20 by means of a suitable cable 240. This cable is strung over a seriesof pulleys 241, 242 and 243 such that vertical movement of the latchresults in substantially vertical movement of the vertical barrier 20.The latch itself is a hooked shaped member 232. In the latched positionshown in FIG. 9, that hook member 232 is engaged over a vertical wall233 in the carriage 30. Extending upwardly from the hook shaped member232 is a metal eye 235. The metal eye 235 is adapted to be engaged by alifting handle 250 for the purpose of unlatching the latch mechanism 230and allowing the vertical barrier 20 to move to its operative,vehicle-restraining position.

To achieve unlatching, the hook member 232 is manually moved upwardlyand to the right, in the sense of FIG. 10. With the latch member 232positioned to the right of retaining wall 233, the latch can now movedownward vertically into the guide channel 260 formed by horizontalplate 262 and vertical plate 263. As the latch 232 is moved downwardly,the spring 200 exerts an upward force on the vertical barrier 20 thusmoving it toward the operative position.

To move the vertical barrier to the inoperative from the operativeposition, and to secure it in place, the lifting handle 250 is againused to engage the eye 235. The hook member 232 is thus moved upwardlywithin guide channel 260 until the hook member 232 can be engaged withretaining wall 233 thus latching the vertical barrier 20 into itsinoperative position.

There is thus provided both a powered and non-powered embodiment of thevehicle restraint according to the present invention. The vehiclerestrain includes an independently moveable carriage and employs asimplified vehicle restraining member which is housed within thatcarriage. Further, the driver for moving the vehicle restraining member,in both embodiments is simple in construction and does not occupy anundue amount of space inside the carriage. Furthermore, by virtue of thefact that the driver is releasably engaged to the vertical barrier, thedrive is less susceptible to damage from uncontrolled carriage movement,or from a force exerted on the vehicle restraining member from effortsto move the restrained vehicle. The vehicle restraint is simple inconstruction and includes advantageous safety and signalling features.

What is claimed is:
 1. A vehicle restraint for securing a vehicle parkedon a roadway adjacent a loading structure, comprising in combination:acarriage mounted for substantially vertical movement relative to theloading structure, and including a horizontal top surface, the carriagebeing biased to yieldably assume an elevated position, and movabledownwardly from the elevated position by an external force being exertedon the carriage; a barrier mounted within the carriage for movementbetween an inoperative vehicle-release position wherein the barrier isdisposed within the carriage, and an operative vehicle-restrainingposition wherein at least a portion of the barrier extends above thehorizontal top surface of the carriage to thereby restrain the vehiclefrom moving away from the loading structure; a sensor member mountedadjacent the horizontal top surface of the carriage, and mounted forreciprocating movement with respect thereto between a depressed positionand an extended position wherein at least the upper surface of thesensor extends above the horizontal top surface of the carriage, thesensor member being disposed such that contact of the vehicle with thesensor member moves the sensor member to the depressed position; acontact switch coupled to the sensor member for movement therewith; anda switch-engaging member on the barrier, and disposed to contact thecontact switch when the sensor member is in the depressed position andthe barrier is extended to the operative vehicle-release position, suchcontact generating a signal.
 2. The vehicle restraint of claim 1,wherein the sensor member has an upper horizontal surface parallel tothe horizontal top surface of the carriage, and is mounted within thecarriage for reciprocating vertical movement with respect theretobetween a depressed position wherein the horizontal top surface of thesensor member is flush with the horizontal top surface of the carriage,and an extended position.
 3. The vehicle restraint of claim 2, andincluding a biasing device for biasing the sensor member into theextended position.
 4. The vehicle restraint of claim 1, wherein thecontact between the switch-engaging member and the contact switchgenerates a signal which is representative of a vehicle lockedcondition.
 5. The vehicle restraint of claim 1, wherein the barrier is avertically elongate barrier mounted within the carriage remote from saidupright loading structure to define a vehicle capture distance, saidvertical barrier being mounted for substantially vertical movement withrespect to the carriage between the inoperative and operative positions.